RCA Spectra 70 - Page 154

Convert to Binary
(CVB)
General Description
Format
(RX)
Condition Code
Interrupt
Action
Notes
Fixed-Point
Instructions
• The radix of the double-word operand in main memory specified by the
second address (X
2
/BdD
2
)
is converted from decimal to binary notation
and loaded into the general register specified by the first address (R
1
).
The operand in main memory is treated as a right-justified signed integer
before and after the conversion.
o
7 8 11 12 15 16 19 20
31
• Unchanged.
• Address error:
Addressing.
Specification.
Data error.
Divide error.
• 1. The double-word operand in main memory (15 digits plus sign)
must be in the packed decimal format. The operand is checked for
valid sign and digit codes. The sign representation depends on the
current decimal code (USASCII or EBCDIC).
2. The maximum decimal number that can be converted and still be
contained
in a 32-bit register is (2,147,483,647) 10 positive and
(2,147,483,648) 10 negative. A larger decimal number causes a divide
error interrupt.
3. Negative decimal zero is converted to positive binary zero.
4. The
operand specified by the second address remains unaltered in
main memory.
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